Hermetic electrically driven compressor

ABSTRACT

Contact noise occurring continuously in a hermetic electrically driven compressor is reduced.  
     A stopper  106  has a protrusion  106 A projecting along the vertical direction at the inner circumferential side formed by draw forming. If vibration or impact is applied to a electrically driven compressor body  107  from outside during operation of the electrically driven compressor body  107 , the upper end portion of a crankshaft  105  prevents continuous rotary motion along the inner circumferential side of the stopper  106 . As a result, occurrence of noise can be reduced.

FIELD OF THE INVENTION

[0001] The present invention relates to a hermetic electrically driven compressor used in refrigerator, freezer, air conditioner, dehumidifier, etc.

BACKGROUND OF THE INVENTION

[0002] A conventional hermetic electrically driven compressor comprises an enclosed container, and motor elements and compressor elements included in this enclosed container. Such conventional hermetic electrically driven compressor (hereinafter called compressor) is disclosed, for example, in Japanese Laid-open Patent No. H11-303740 or U.S. Pat. No. 5,118, 263.

[0003] A conventional compressor is described below while referring to the drawing.

[0004]FIG. 4 shows a compressor 10, in which an enclosed container 20 is formed of an upper case 20A and a lower case 20B joined by welding or the like at mutual open edges.

[0005] A electrically driven compressor body (hereinafter called compressor body) 30 is elastically supported and contained in this enclosed container 20 by way of a plurality of elastic support devices 40. A motor element 50 is disposed in the upper part in the enclosed container 20, and includes a stator 60 and a rotator 70. A compressor element 80 is disposed in the lower part in the enclosed container 20. A crankshaft 90 for coupling the compressor element 80 and motor element 50 is provided on the rotator 70.

[0006] A stopper 100 for inserting the upper end portion of the crankshaft 90 is disposed in the upper part in the enclosed container 20.

[0007] In the compressor configured in this manner, its operation is described below. The upper end portion of the crankshaft 90 is inserted into the center of the inside of the stopper 100 fitted to the upper part in the enclosed container 20.

[0008] Thus, when transporting the compressor 10, the compressor body 30 is prevented from swinging to contact with the inside of the enclosed container 20. As a result, the compressor body 30 is protected.

[0009] In the conventional structure, the condition of mounting and fixing the compressor 10 to the refrigerator includes the following. In addition to the hardness and mounting condition of the vibration absorbing rubber prevent transmission of vibration of the compressor 10, the rigidity of piping connection is involved. When these mounting and fixing conditions are stronger, the enclosed container 20 is fixed more firmly.

[0010] In these mounting conditions, when impact or vibration is applied from outside during operation of the compressor body 30, the following phenomenon occurs. By the motion of the elastically supported compressor body 30, the upper end portion of the crankshaft 90 hits against the inner circumferential side of the stopper 100.

[0011] By the rotating force of the crankshaft 90 and the friction of the inner circumferential side of the stopper 100, the crankshaft 90 repulses, and hits against the inner circumferential side of the stopper 100 by this repulsive reaction. This state occurs repeatedly, and noise is generated due to contact by rotary motion along the inner circumference of the stopper 100.

[0012] The invention is intended to solve these conventional problems, and present a compressor capable of suppressing occurrence of noise.

SUMMARY OF THE INVENTION

[0013] The invention presents a hermetic electrically driven compressor comprising a compressor element elastically supported in an enclosed container, a crankshaft provided with said compressor element, a motor element for driving said compressor element, and a cup-shaped stopper fixed to the inside upper part of said enclosed container and having a protrusion at its inner circumferential side, wherein the upper end portion of said crankshaft extends into said stopper.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a longitudinal sectional view of a compressor in accordance with a first exemplary embodiment of the present invention.

[0015]FIG. 2 is a perspective view of a stopper of the compressor in accordance with a first exemplary embodiment of the present invention.

[0016]FIG. 3 is a perspective view of upper part of enclosed container of a compressor in accordance with a second exemplary embodiment of the present invention.

[0017]FIG. 4 is a horizontal sectional view of upper part of enclosed container of a compressor in accordance with a second exemplary embodiment of the present invention.

[0018]FIG. 5 is a longitudinal sectional view of a conventional compressor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Preferred embodiments of the compressor of the present invention are described below while referring to the accompanying drawings. Same parts as in the prior art are identified with same reference numerals, and detailed description is omitted. The drawings are schematic ones and they do not indicate dimensional relations of the elements.

[0020] (Exemplary embodiment 1)

[0021] As shown in FIG. 1, inside an enclosed container 101, a compressor element 103 elastically supported by a spring 102, and a motor element 104 fixed at the upper side of the compressor element 103 for driving it are provided.

[0022] The compressor element 103 includes a compressor chamber 109, and a piston 108 reciprocating in the compressor chamber 109.

[0023] A cup-shaped stopper 106 is fixed to the inside upper part of the enclosed container 101. The upper end portion of a crankshaft 105 extends into the stopper 106. The stopper 106 is fitted with a space to the upper end portion of the crankshaft 105 composing the compressor element 103. The space is approximately 2-10 mm. As shown in FIG. 2, a protrusion 106A is formed at the inner circumferential side of the stopper 106. The protrusion 106A projects to the inside by draw forming of the stopper 106. The protrusion 106A is formed in a shape of a groove along the vertical direction, and the leading end of the protrusion 106A is formed in a curvature. Thus, the protrusion 106A is formed integrally with the stopper 106 by draw forming. It is easy to form the protrusion, without an extra cost. In this structure, the operation is described.

[0024] During operation of the compressor, due to fluctuation of compressor load or an external force appling to the enclosed container 101, the compressor element 103 elastically supported by the spring 102 oscillates. As a result, the upper end portion of the crankshaft 105 may contact with the inner circumference of the stopper 106. At this time, by the own rotation of the crankshaft 105, its contact portion with the stopper 106 is moved, and continuously rotates by rubbing against the inner circumference of the stopper 106. According to the present invention, however, the upper end portion of the crankshaft 105 collides against the protrusion 106A, and by the reaction of this collision, it further collides against the inner circumference of the stopper 106. As a result, occurrence of continuous rotary motion is prevented. Thus, generation of noise due to collision can be prevented, and the refrigerator or the like using the compressor of present exemplary embodiment does not give any unpleasant feeling to its user.

[0025] The protrusion 106A has a vertical groove shape. Therefore, if the compressor element 103 elastically supported by the spring 102 is moved vertically, the protrusion 106A and the upper end side of the crankshaft 105 collide against each other securely. Further, the leading end of the protrusion is a curved surface instead of an edge, and the rigidity of the protrusion is enhanced. As a result, if the protrusion 106A collides against the leading end of the crankshaft 105, it is not deformed.

[0026] (Exemplary embodiment 2)

[0027] Exemplary embodiment 2 is described while referring to FIG. 1 and FIG. 4.

[0028] A compressor element 103 is elastically supported by springs 102 provided in supporting parts 110A, 110B, 110C, and 110D. Line segment A-A′ shown in FIG. 4 shows the direction of reciprocal motion of the piston. Line segment B-B′ shows nearly the center between the supporting parts 110A and 110B, and 110C and 110D. Line segment C-C′ indicates a line vertical to line segment A-A′ through the nearly central axis of the crankshaft 105 and stopper 106.

[0029] In the present exemplary embodiment, as compared with the compressor of exemplary embodiment 1, protrusion 106A is formed as shown in FIG. 3 and FIG. 4. The protrusion 106A is provided in a direction nearly vertical to the direction of reciprocal motion of the piston 108 indicated by line segment A-A′.

[0030] The compressor of the present exemplary embodiment having such configuration has a cup-shaped stopper 106 fitted with a space to the upper end portion of the crankshaft 105 composing the compressor element 103. The space is approximately 2-10 mm. The protrusion 106A is formed at the inner circumferential side of the stopper 106. Accordingly, by the repulsion of rotating force of the crankshaft 105, when the upper end portion of the crankshaft 105 starts rotary motion along the inner circumference of the stopper 106, the upper end portion of the crankshaft 105 collides against the protrusion 106A. By the reaction of this collision, the upper end portion of the crankshaft 105 returns to the normal position of the stopper 106 fitted with a space, so that rotary motion can be prevented.

[0031] The specific effect of the present exemplary embodiment is more specifically described by referring to FIG. 4. The compressor element 103 has its center of gravity near the compressor chamber 109, and a greater load is applied to the spring 102 at the compressor chamber 109 side corresponding to the left side from line segment B-B′.

[0032] On the other hand, the center of gravity of the motor element 104 is positioned near the axis of the crankshaft 105, and a greater load is applied to the spring 102 at the anti-compressor chamber 109 side corresponding to the right side from the line segment B-B′.

[0033] In particular, when starting or stopping the compressor, the vicinity of center of gravity of the compressor element 103 disposed in the lower part of the enclosed container 101 and the vicinity of center of gravity of the motor element 104 disposed in the upper part of the enclosed container 101 oscillate in turn. Consequently, a large vibration may occur, and a large vibration occurs in the direction of line segment A-A′ nearly coinciding with the linking the centers of gravity of the compressor element 103 and motor element 104. As a result, when starting or stopping the compressor, if the spacing between the crankshaft 105 and stopper 106 is narrow, they collide against each other, and a loud impulse sound is generated. In the present exemplary embodiment, by contrast, the protrusion 106A is provided in a direction vertical to the direction of line segment A-A′ as shown in FIG. 3. There is a relative wide space between the crankshaft 105 and stopper 106, therefore it can lower the possibility of collision of them. That is, the present exemplary embodiment has an original effect of reducing the noise at the time of start and stop of the compressor, in particular.

[0034] As explained herein, according to the present invention, continuous rotary motion occurring between the crankshaft 105 and stopper 106 can be prevented, and occurrence of noise can be reduced.

[0035] The compressor of the present invention can be used widely in refrigerator, freezer, air conditioner, dehumidifier, etc. 

What is claimed is:
 1. A hermetic electrically driven compressor comprising a compressor element elastically supported in an enclosed container, a crankshaft provided with said compressor element, a motor element for driving said compressor element, and a cup-shaped stopper fixed to the inside upper part of said enclosed container and having a protrusion at its inner circumferential side, wherein the upper end portion of said crankshaft extends into said stopper.
 2. The hermetic electrically driven compressor of claim 1, wherein said protrusion is formed integrally with the stopper by draw forming.
 3. The hermetic electrically driven compressor of claim 1 or 2, wherein said protrusion is formed in a groove shape along the vertical direction of the stopper inside.
 4. The hermetic electrically driven compressor of claim 1 or 2, wherein the leading end portion of said protrusion is formed in a curvature.
 5. The hermetic electrically driven compressor of claim 3, wherein the leading end portion of said protrusion is formed in a curvature.
 6. The hermetic electrically driven compressor of claim 1 or 2, wherein said compressor element includes a compressor chamber and a piston moving reciprocally in the compressor chamber, and said protrusion is provided in a direction nearly vertical to the direction of reciprocal motion of the piston.
 7. The hermetic electrically driven compressor of claim 3, wherein said compressor element includes a compressor chamber and a piston moving reciprocally in the compressor chamber, and said protrusion is provided in a direction nearly vertical to the direction of reciprocal motion of the piston.
 8. The hermetic electrically driven compressor of claim 4, wherein said compressor element includes a compressor chamber and a piston moving reciprocally in the compressor chamber, and said protrusion is provided in a direction nearly vertical to the direction of reciprocal motion of the piston.
 9. The hermetic electrically driven compressor of claim 5, wherein said compressor element includes a compressor chamber and a piston moving reciprocally in the compressor chamber, and said protrusion is provided in a direction nearly vertical to the direction of reciprocal motion of the piston. 